As fresh water resources grow increasingly scarce, water quality is rapidly becoming a major global concern. In addition to high levels of pollution from industrial and municipal sources and saltwater intrusion into fresh water acquifers, commonly used disinfectants in drinking water, particularly free chlorine (in the form of HOCl/OCl−) and monochloramine (NH2Cl), react with metals and metalloids to produce soluble products. Monochloramine, for example, is believed to react with lead to produce soluble Pb(II) products, leading to elevated Pb levels in drinking water.
Various technologies have been used to remove contaminants from municipal, industrial, and recreational waters. Examples of such techniques include adsorption on high surface area materials, such as alumina and activated carbon, ion exchange with anion exchange resins, co-precipitation and electrodialysis. However, most technologies for contaminant removal are hindered by the difficulty of removing problematic contaminants, more particularly the difficulty of removing metal and metalloid contaminant species.